package main

import (
	"fmt"
	"os"
	"runtime"
	"runtime/debug"
	"runtime/trace"
	"time"
)

func printGCStats() {
	t := time.NewTicker(time.Second)
	s := debug.GCStats{}
	for {
		select {
		case <-t.C:
			debug.ReadGCStats(&s)
			fmt.Printf("gc %d last@%v, PauseTotal %v\n", s.NumGC, s.LastGC, s.PauseTotal)
		}
	}
}

func printMemStats() {
	t := time.NewTicker(time.Second)
	s := runtime.MemStats{}

	for {
		select {
		case <-t.C:
			runtime.ReadMemStats(&s)
			fmt.Printf("gc %d last@%v, next_heap_size@%vMB\n", s.NumGC, time.Unix(int64(time.Duration(s.LastGC).Seconds()), 0), s.NextGC/(1<<20))
		}
	}
}

func allocate() {
	_ = make([]byte, 1<<20)
}

func main() {
	// go printGCStats()
	// go printMemStats()

	f, _ := os.Create("trace.out")
	defer f.Close()
	trace.Start(f)
	defer trace.Stop()

	for n := 1; n < 100000; n++ {
		allocate()
	}
}